Oil leaks in South Dakota

After petroleum (oil) is extracted from wells, it is transported by rail cars, trucks, tanker vessels, and through pipelines. When it is carried through pipelines, pipelines sometimes spring leaks and cause environmental problems. An oil leak was discovered on April 9, 2016, in South Dakota, and the spill was measured 16,800 gallons. The pipelines run underground so it may have contaminated not just land but local groundwater.

In 2013, the same pipeline had a 840,000 gallons of oil leak in North Dakota. How much more oil was spilled in the incident in 2013 than 2016?

Together, how many gallons of oil was spilled?

A tanker truck carries 9,000 gallons of oil. How many trucks can be filled with the oil that spilled in 2013?